effect of guar and carboxymethyl cellulose thickening agentson the physical and rheological properties of set fruit yogurt

in this study, wasinvestigated the effect of two thickening agents, carboxymethyl cellulose (cmc) and guar on the rheological properties of set fruit yogurt. viscoelastic modulus (g' , g'), apparent viscosity and complex viscosity increased and loss factor decreased by increasing carboxymethyl cellulose and guar content up to 0.2% and 0.06% respectively. however, in the concentrations greater than these amounts, the contradictory results were observed. also by adding cmc and guar to fruit yogurt, syneresis and water holding capacity decreased and increased respectively.in spite of possitive effect of two thikening agents on rheological properties, addition of mixture of them had negative effect.by increasing of different proportion of cmc in constant concentrations of guar (0.02% and 0.04%)no synergistic effect on improvement of three-dimensional yogurt structure was observed and rheological properties and water holding capacity weakened and syneresis increased.